<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
    <script src="../vue.js"></script>
    <style>
        .v-enter,.v-leave-to{
            opacity: 0;
        }
        .v-enter-active,.v-leave-active{
            transition:opacity 1s;
        }
    </style>
</head>
<body>
<div id="app">
    <transition-group>
        <div v-for="item of list" :key="item.id">
            {{item.title}}
        </div>
    </transition-group>
    <button @click="handleBtnClick">Add</button>
</div>

<script>
    var count=0;
    var vm = new Vue({
        el: "#app",
        data: {
            list:[]
        },
        methods:{
            handleBtnClick: function () {
                this.list.push({
                    id:count++,
                    title:'hello world'
                })
            }
        }
    })
</script>
</body>
</html>